<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        .sky{
            width: 600px;
            height: 600px;
            background-color: pink;
        }
        .moon1{
            width: 400px;
            height: 400px;
            background-color: yellow;
            border: dotted 4px ;
            /*【1】此处将会看到背景色会进入边框。*/
        }
        strong{
            border-top: solid thick pink;
            border-bottom: solid thin green;
            border-left: 25px double gray;
            background-color: silver;
        }
    </style>
</head>
<body>
<div class="sky">
    <p class="moon1">
        this is a pragrah for color and test
        <strong>我们来试验下行内非替换元素的边框问题</strong>
        this is a pragrah for color and test
        this is a pragrah for color and test
    </p>
</div>
</body>
</html>